Gold Testers Compared: Which One Do You Actually Need?

For most people buying coins and bars, the best gold tester is a set of cheap tools used together: a digital scale, a pair of calipers and a strong magnet, under $50 in all. Together they catch most fake coins, because fakes rarely get weight, size and metal right at once. Add a free ping-test app for coins. To catch the dangerous fake, a gold-plated tungsten bar or coin, you need a Sigma Metalytics verifier, which costs about $900 and up. Acid kits and electronic testers are for jewelry and read only the surface. XRF analyzers ($17,000 and up) tell you the karat, but also only at the surface.

No single tester catches every fake. Each one measures one property, such as weight, sound, conductivity or the elements on the surface, and a good counterfeit is built to pass the test its maker expects. The trick is to pick tests that measure different things.

Which gold tester should you buy?

It depends on what you own and what kind of fake you are worried about. Here are the common testers, with the price ranges listed by the Anti-Counterfeiting Educational Foundation, an industry group set up to fight fake bullion:

How do the cheap tests work, and what do they miss?

Scale and calipers

Every bullion coin has a published weight, diameter and thickness. A fake made of a cheaper metal can match one of those, sometimes two, but rarely all three, because the cheaper metal is lighter or heavier for its size. That is why a scale that reads to 0.01 gram and a pair of digital calipers catch most fake coins. Our Is My Coin Fake? checker compares your readings with the mint’s specifications for twenty common coins.

Magnet

Gold and silver are not magnetic. A strong neodymium magnet that grabs a coin tells you it contains iron, nickel or cobalt. A magnet that doesn’t grab tells you very little, because copper, brass, lead and tungsten aren’t magnetic either. For silver there is a better trick: slide the magnet down a tilted silver bar and it slows down, a property of silver you can see.

Ping test

Balance a coin on a fingertip, tap it with another coin and it rings. The pitch depends on the coin’s size, shape and metal. Apps such as Pingcoin record the sound and compare its frequencies with genuine coins of the same type. Pingcoin itself says the test is “not foolproof”: a counterfeit struck from the right metal at the right size sounds right, and mixing metals, such as a tungsten core inside gold, can move the pitch closer to genuine. Use it as one test among several.

Specific gravity

Weighing an item in air and then in water gives its density. Gold is about 19.3 grams per cubic centimeter, far heavier than copper or brass, so most fakes fail. Our guide to telling if gold is real at home shows how with a kitchen scale. The weakness is tungsten, at about 19.25, almost exactly as dense as gold.

Which testers tell you the karat of jewelry?

Acid kits are the old jeweler’s test: rub the piece on a black testing stone and drop acid of a known strength on the streak. If the streak survives the 14K acid, the gold is at least 14K. Kits cost $12 to $50. They test only the streak you rubbed off, so a gold-plated piece passes unless you file through the plating, and they scratch, so they’re for jewelry and scrap, never for coins.

Electronic gold testers measure how well the metal conducts electricity and match it to a karat table. They are quick and leave no mark on most pieces. A UK seller who reviewed nine of them found the better ones accurate to about one karat at the low end and two at the high end. Every one of them tests only the surface, so file through any plating first. Our guide to gold and silver stamps tells you what the mark on the piece is supposed to mean.

If you are selling, you may not need either. Most gold buyers test what they buy, often in front of you and usually for free.

Sigma verifier or XRF: what do dealers use?

A Sigma Metalytics Precious Metal Verifier sends an electromagnetic signal into a coin or bar and measures how the metal responds. Its wands read different depths, from about 0.18 millimeters to 2.5 millimeters, and the Pro model’s bridge reads through a whole bar up to 100 ounces. That depth is what catches a gold-plated tungsten core, and it reads through plastic capsules and slabs. Sigma itself warns that the device “should not be the sole means” of identifying a counterfeit, because other materials can share gold’s resistivity, so pair it with weight and size. It is not made for jewelry. The original model runs about $900 to $1,800; Money Metals listed the Pro set at $3,499.99 on November 7, 2026.

An XRF analyzer fires X-rays at the surface and reads back the exact elements, which makes it the best tool for telling 14K from 18K. Because the reading comes from the surface, a thick layer of real gold over another metal can pass. Some XRF models add plating checks, but none is cheap: $17,000 to $50,000.

The rule of thumb: Sigma for coins and bars, XRF for jewelry, and a scale and calipers for everyone.

Can any single test catch every fake?

No, and the makers say so. The most dangerous fakes, gold-plated tungsten bars and coins, are built to the right weight and size, so a scale, calipers and a water test all pass them. A magnet passes them too. What catches them is a test that looks below the surface (a Sigma verifier or an ultrasonic gauge) or, for coins, the ping test. A $20 acid kit would pass the plating.

So combine tests that measure different things: weight and size, plus sound or conductivity. A fake that beats all of them at once costs its maker more than most fakes are worth.

What about silver?

The same tools work, with two differences. Silver is light for its size, so tungsten is a poor match and most fake silver is plated copper, brass or a zinc alloy, which a scale, calipers and the magnet slide test catch. A Sigma verifier reads silver too, through capsules. Our guide to telling if silver is real has the silver tests step by step, and our guide to vintage silver bars describes the lead-cored fakes of old Engelhard bars.

Outside the US

In the UK, gold and silver jewelry above small weight limits must carry a hallmark from one of the four assay offices, which have already tested it, so the hallmark is the first thing to check. Several mints add their own security features: PAMP’s Veriscan app checks PAMP bars, and the Royal Canadian Mint and others use micro-engraving and other marks on newer coins. Those checks only work for that maker’s products.

Sources

• Price ranges, what each test detects and its limits: Anti-Counterfeiting Educational Foundation, Counterfeit testing chart, updated May 15, 2024.
• Sigma Metalytics PMV Pro: wand depths (0.18, 0.25 and 2.5 mm), the bridge for bars up to 100 oz, testing through plastic, the limits quoted and the $3,499.99 price: Money Metals product page, read November 7, 2026.
• How the ping test works and its false positives: Pingcoin, False positives.
• Electronic tester accuracy and surface-only readings: Quicktest, Reviews of nine electronic gold testers (a UK seller of testers); Dynagem, Electronic gold testers.
• Gold density 19.3 g/cm³ and tungsten 19.25 g/cm³: as cited in our guide to telling if gold is real.

Questions people actually ask

What is the best gold tester for home use?

For coins and bars, a digital scale that reads to 0.01 gram, a pair of digital calipers and a strong magnet, used together, for under $50. For jewelry, an acid kit or an electronic tester, after filing through any plating.

Do electronic gold testers work?

Yes, for the karat of jewelry, roughly to within one or two karats on the better models. They measure only the surface, so a plated piece can read as gold unless you file through the plating first.

Can a gold tester detect gold-plated tungsten?

Most can't. Tungsten is almost exactly as dense as gold, so a scale and a water test pass it, and acid and electronic testers only read the gold plating. A Sigma Metalytics verifier, which reads below the surface, or an ultrasonic gauge for bars is what dealers use.

How do dealers test gold?

Most use several tests: weight and size against the specification, a Sigma Metalytics verifier for coins and bars, and an XRF analyzer or acid for jewelry. Many will test a piece in front of you for free.

Is the acid test accurate?

It is accurate for the metal you scrape onto the stone, which is why jewelers still use it. It can't see under the surface, so plated items pass unless filed, and it scratches, so never use it on a coin.

Is the ping test reliable?

It catches coins made of the wrong metal, which ring at the wrong pitch. Pingcoin, which makes a ping app, says it is not foolproof: a counterfeit of the right metal and size sounds right. Use it with a scale and calipers.

How much does a Sigma gold tester cost?

The original Sigma Metalytics Precious Metal Verifier runs about $900 to $1,800 depending on the set. Money Metals listed the PMV Pro full set with the bar bridge at $3,499.99 on November 7, 2026.

What is the difference between a Sigma verifier and XRF?

A Sigma verifier checks whether a coin or bar behaves like its metal below the surface, which catches tungsten cores. An XRF analyzer names the exact elements on the surface, which tells 14K from 18K. Sigma suits bullion; XRF suits jewelry.

Does a magnet test prove gold is real?

No. A magnet that sticks proves a piece is fake, but one that doesn't stick proves little, because copper, brass, lead and tungsten aren't magnetic either.